ECU recieving constant voltage instead of injector pulses

[FiIiAiT2000]

Ive been trying to get my 1981 FI spider to idle for a while now. So far it runs really rough and tue accelerator just causes it to shut down. Ive been testing the signal from the ignition coil to the ecu. The troubleshooting manual says i should be seeing a flickering voltage at ecu terminal 1 when I start the motor, but instead Im getting a constant 12v with the ignition in the "on" position and then a drop when I start it, which i think is just the draw from the starter and then it goes back up to 12v.

I tested the wire that connects terminal 1 to the ignition coil and its good so now im just wondering if anyone has a clue as to why it might be giving me this constant 12v instead of pulsing.

Thanks!

[RRoller123]

If you are using a standard DVM multi-gauge, it can't respond fast enough to see the pulses, I think. A Noid light works. As another really easy alternative, you can put a mechanics stethoscope (a couple bucks at HF) on the injectors and listen to them as they click open and shut. The sound is very clear and hard to miss. If they are silent, then they are either always open or always closed, as you suspect.

[FiIiAiT2000]

I just tested the one of the injectors with a noid light and it was dim but was on constantly. I did see two flashes during one startup that indicated a signal but it only happened once and all the other times i got just the constant dim light. I guess this means the injectors are only slightly open? Which would make sense since the engine is idling but just barely.

[FiIiAiT2000]

Im thinking the problem might be with the ignition control module as that sends the pulses. Tested the mag pickup and got 700 ohm so thats good.

[FiIiAiT2000]

Would the engine still fire with a bad ICM or should I be looking somewhere else? I just read somewhere on one of these threads that it controls the pulses but I'm not sure if thats correct.